5 Answers
5

1.yes but not completely

It will depend on how much it is scratched . If it is negligible just ignore it
. If it is in the moderate level some utility programs may help you . If it is in very high level no hope , (still you may can recover some data if you have luck :) )

2.Try your luck using following apps

CD Recovery Toolbox Free
CD Recovery Toolbox Free was developed for recovering damaged files CD, DVD, HD DVD, Blu-Ray and etc disks. You can use it to restore information lost as a result of some mechanical damage of the disk (scratches, chips, different spots on the surface) or as a result of incorrect recording. Program can recover data that was considered lost. Tool scans any CD and DVD disks and finds files and folders located there

Recovers files from disks with physical damage. Allows you to copy files from disks with problems such as bad sectors, scratches or that just give errors when reading data. The program will attempt to recover every readable piece of a file and put the pieces together. Using this method most types of files can be made useable even if some parts of the file were not recoverable in the end.

Or Try to fix the DVD

First clean the surface of the disc with a soft lint-free cloth. You can use a gentle detergent (or rubbing alcohol) if there are some grease spots. Make sure there are no finger prints or dust particles. Don’t scrub too hard as you may do more harm than good this way.

Now apply some toothpaste or polish on the scratched surface. It is best to start with a minimum amount of either, or else you will have your work really cut out trying to buff away the remainder.

+1 for Unstoppable Copier, that software is fantastic for grabbing data off bad/dying drives as well.
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Evan WondrasekMay 29 '12 at 14:21

1

Yeah, the important thing, when trying to remove scratches, is to NOT do circular motions, which will tend to put new microscratches parallel to the recording tracks but instead use radial (in-out) motions. And likely a Radio Shack or Best Buy near you has a kit for scratch removal.
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Daniel R HicksOct 10 '13 at 23:41

Not necessarily. The data is not actually stored on the surface of the disk - it's actually stored more towards the center. There is a protective layer of plastic-coating (polycarbonate) surrounding the data.

How do I fix a scratched DVD?

If only the protective layer is scratched, it can be filled in using the CD/DVD repair kits available at electronics stores (or even Wal-mart). If the scratch is deep enough to damage the data, however, you're out of luck.

(Others have mentioned that DVDs use error-correction codes. This is true, but if the drive is saying the data is corrupt/can't be read, that already means the ECC wasn't able to recover the data, so that knowledge does not really help you)

1- Yes, all DVD/CD are burned using a digital redundancy technique. On DVDs I know that Reed-Solomon code is used:

Reed–Solomon codes have since found important applications from
deep-space communication to consumer electronics. They are prominently
used in consumer electronics such as CDs, DVDs, Blu-ray Discs, in data
transmission technologies such as DSL and WiMAX, in broadcast systems
such as DVB and ATSC, and in computer applications such as RAID 6
systems.

This code allow you to have some scratches on your DVD/CD because data redundancy, however it goes only to a limit(not deterministic), after that, every new scratch will result on more data loss.

2- Fortunatelly there are some methods that allow you to try to recover your scratched media and the data on it. On Wikihow you can found a good way:

While compact discs (CDs) are remarkably durable, it’s nearly
impossible to prevent scratches and scuffs from occurring from time to
time, especially with frequent use. The resulting damage can mean
either a skip in your favorite music track or, in the case of data
CDs, the loss of that spreadsheet you worked on for two weeks.

Don’t despair — repair! While commercial CD repair kits and CD
refinishing machines are available, you may be able to repair the
damage on your own with products you already have.

Scratches on the bottom (clear) portion of the disk cause data read errors by interrupting the laser beam's path to the data. The actual data may still be intact, just unreachable (think overwriting words on a page with a black marker, the words are still there but not visible.) Such scratches may be filled in or polished out using various products/techniques. Try googling for "CD repair".

Scratches on the top (metallic) portion of the disk actually remove the data bearing layer and are not physically recoverable. If you can see light through the disk, the data is no longer there.

In either case the error correction protocols noted in other answers are used to rebuild lost data, up to a point.

Also, Disks with surface damage on the bottom can fairly easily be repaired, a lot of Movie rental places have a machine that can resurface disks and make them work again.
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Jeff F.May 23 '12 at 16:21

1

"Such scratches may be filled in or polished out using various products/techniques. Try googling for "CD repair"." Good point about the rental place though, you may try asking your local rental place if they are willing to process your disk.
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Chris NavaMay 23 '12 at 17:30

Yes, it can cause. Depends on the location/depth/type of the scratch. But yes, it may cause data loss. (Even if the DVD features a "Scratch protection layer".)

You can't repair a damaged DVD. Back in the days, we used Alcohol 120% software to read the DVD even with the damaged blocks, and managed to save the data. You can give that a try.

To prevent all this:
You can use WinRAR's "Recovery record". If the DVD gets damaged, and if the corrupted part falls under the recovery record, WinRAR will be able to repair the archive itself.
(You can enable it at the "General" tab of "Add to archive", and set the Recovery record's percentage at the "Advanced" tab. How much? Depends on how big your data is.)

On bad scratches I used a dab baby oil on the scratches to help the laser read the blocks, worked amazingly well, clear fingernail polish works well also, but is a more permanent solution that requires dry time. Then there is polishing the disc to remove light to moderate scratches.
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MoabMay 23 '12 at 13:49

2

I disagree on 2. You can fix damaged DVD as long as it is surface damage. A lot of movie rental places have a machine that will resurface a DVD and restore it to like new condition.
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Jeff F.May 23 '12 at 16:23